U.S. patent number 4,470,322 [Application Number 06/302,968] was granted by the patent office on 1984-09-11 for steering column with adjustable tilt head and steering wheel assembly.
This patent grant is currently assigned to General Motors Corporation. Invention is credited to Howard D. Beauch.
United States Patent |
4,470,322 |
Beauch |
September 11, 1984 |
Steering column with adjustable tilt head and steering wheel
assembly
Abstract
Steering column with tilt head having tilt locking and release
dog controlled by manual lever operable in camming slot therein and
normally biased by spring to an over-tilt center position for
positive locking of the tilt head in selected tilt position.
Inventors: |
Beauch; Howard D. (Hemlock,
MI) |
Assignee: |
General Motors Corporation
(Detroit, MI)
|
Family
ID: |
23170018 |
Appl.
No.: |
06/302,968 |
Filed: |
September 17, 1981 |
Current U.S.
Class: |
74/493;
74/535 |
Current CPC
Class: |
B62D
1/184 (20130101); Y10T 74/20684 (20150115) |
Current International
Class: |
B62D
1/18 (20060101); B62D 001/18 (); G05G 005/06 () |
Field of
Search: |
;74/493,535
;280/775 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
231839 |
|
Feb 1964 |
|
DE |
|
0053962 |
|
May 1981 |
|
JP |
|
Primary Examiner: Staab; Lawrence J.
Assistant Examiner: Gonet; Michael J.
Attorney, Agent or Firm: White; Charles R.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A steering column for a vehicle comprising upper and lower
steering shafts, universal joint means pivotally interconnecting
said shaft so that said shafts can be turned as a unit for vehicle
steering and so that said upper shaft can be tilted about a
generally horizontal pivot axis to a plurality of angular positions
with respect to said lower shaft, a steering wheel secured to the
free end of said upper shaft for rotating said upper and lower
shafts, tubular mast jacket means mounted in the vehicle and
disposed around said lower shaft, a tilt head support secured to
the upper end of said mast jacket means and projecting therefrom
around said universal joint means, a tilt head assembly disposed
around said upper shaft, pivot means pivotally mounting said tilt
head assembly to said tilt head support for tilting movement with
said upper shaft about said horizontal pivot axis, locking dog
lever means having one end pivotally connected to the tilt head
assembly and having a plurality of locking teeth at the free end
thereof for releasably locking said tilt head assembly in any of a
plurality of fixed angular positions with respect to said tilt head
support, locking teeth means fixed to said tilt head support for
selective locking engagement with the teeth of said locking dog
lever, said locking dog lever having a cam slot therein, a manually
operable actuator lever pivotally mounted in said tilt assembly and
extending through said cam slot means and operative therein to
effect movement of said locking dog means between locking and
unlocking positions, and spring means mounted in said tilt head
assembly engaging said actuator lever for moving said lever to an
end position in said cam slot means in which said tilt head
assembly is positively locked in adjusted position, said locking
dog lever means being centrally mounted in said tilt head assembly
and said locking teeth means comprising a rack of locking teeth
fixed to said support to overlie said universal joint and said
pivot axis.
2. A steering column for a vehicle comprising upper and lower
steering shafts for rotation about a steering axis, universal joint
means pivotally interconnecting said steering shafts so that said
upper shaft can turn said lower shaft and be tilted about a
generally horizontal pivot axis to a plurality of angular positions
with respect to the lower shaft, a steering wheel secured to the
free end of said upper shaft for rotating said upper and lower
shafts, stationary mast jacket means disposed around said lower
shaft, a tilt head support secured to the upper end of said mast
jacket means and projecting axially therefrom, a tilt head assembly
disposed around said upper shaft and rotatably supporting said
upper steering shaft, pivot means pivotally mounting said tilt head
assembly to said tilt head support for tilting movement about said
pivot axis, elongated locking dog means being centrally mounted in
said tilt head assembly and having locking teeth at one end thereof
and further being pivotally connected at the other end for pivotal
movement between locking and unlocking positions with respect to
said tilt head support, said tilt head support having a series of
locking teeth fixed thereto and overlying said universal joint
means for locking engagement with the teeth of said locking dog
means, actuator means for selectively pivoting said locking dog
means to an unlocked position to allow said tilt head assembly and
said upper steering shaft to be tilted as a unit to any one of a
plurality of angular positions, said actuator means comprising a
manually operable actuator lever pivotally mounted in said tilt
head assembly, said locking dog means having cam slot means
receiving and cooperating with said actuator lever means for moving
said locking dog means between locking and unlocking positions, and
spring means in said tilt head assembly contacting said actuator
lever for urging said actuator lever and said locking dog means to
said locking position in which said tilt head assembly is
positively locked in adjusted position for high load resistance.
Description
This invention relates to steering columns and more particularly to
a vehicle steering column with an angularly adjustable tilt head
and steering wheel assembly featuring a new and improved adjustment
and positive locking mechanism for the tilt head and wheel
assembly.
Prior to the present invention, a variety of steering columns have
been provided with tilt heads and steering wheel assemblies to
permit appropriate adjustment by the vehicle operator to various
positions to suit the operator's requirements. While such columns
have provided important benefits for the comfort of the operator
and for improved vehicle operation, the adjustment mechanisms are
often complex in construction and require a large space within a
crowded area within the column and generally provide only a limited
range in which there are only a few adjustment positions.
In this invention a steering column is provided with a new and
improved tilt head and steering wheel assembly which features a
single cam actuated locking and unlocking dog that provides for
simplified positive locking to maintain tilt position under high
load condition and yet can be readily released by the operator for
adjustment by simple motion of a tilt control lever. This invention
provides for the retention of the tilt head in a wider range of
tilt positions as compared to prior art constructions. These tilt
positions are positively maintained with multiple tooth meshing of
locking parts with resulting minimized lash. With this invention
the number of parts are minimized to provide a more compact,
lighter weight and economical tilt control construction. In one
preferred embodiment of this invention, a single spring device is
used to maintain a tilt control lever in operative engagement with
a tilt release and locking dog, and the tilt release and locking
dog in locking engagement with a multi-toothed lock rack.
These and other features, objects, and advantages of this invention
will be more apparent from the following detailed description and
drawing in which:
FIG. 1 is a side view of a portion of a vehicle body broken away to
illustrate a tiltable steering column in accordance with this
invention;
FIG. 2 is a top plan view taken along lines 2--2 of FIG. 1;
FIG. 3 is a side view partially in section taken generally along
lines 3--3 of FIG. 2; and
FIG. 4 is an end view, partly in section with certain parts
removed, taken generally along lines 4--4 of FIG. 3.
With particular reference to FIG. 1 of the drawing, there is shown
a vehicle body 10 which has within its passenger compartment a
steering column assembly 12 that projects through a forward
bulkhead 14. More particularly, the steering column 12 includes
upper and lower tubular jackets 16 and 17 with the lower jacket 17
secured to the bulkhead 14 by a bracket 20. The upper jacket 16 is
mounted to instrument panel construction 18 by bracket 22. The
steering column incorporates a tiltable head 24 having a manually
operated steering wheel 26 operatively mounted thereon. The head 24
and connected steering wheel 26 provides a tilt head assembly which
is adjustable as a unit through a wide angular range and a
plurality of predetermined angular positions with respect to tilt
axis A illustrated in FIG. 3 to facilitate vehicle entry and exit
by the vehicle driver and to maximize driver comfort.
The steering wheel 26 is operatively connected to an upper steering
shaft 28 and retainer nut 29 so that the driver can turn the
steering shaft through the steering wheel for vehicle steering
purposes. This upper shaft is pivotally connected by a universal
joint 30 to a lower steering shaft 32 which extends axially within
the mast jackets into operative connection with vehicle steering
gear in the engine compartment of the vehicle 10.
The tilt head assembly of the steering column has an internal
support cylinder 34 disposed around a portion of the lower steering
shaft 32 and is rigidly secured to an end portion of the upper mast
jacket 16 by threaded fasteners 36 and a suitable retainer, not
illustrated, also secured to the upper end of the jacket 16. In
addition to support cylinder 34, the tilt head assembly
incorporates a large diameter tilt cylinder 38 supporting the upper
steering shaft 28 for rotation therein by internal bearings not
illustrated. The tilt cylinder 38 is pivotally mounted to the
support cylinder for limited tilting movement in a vertical plane,
as indicated by FIGS. 1 and 3 of the drawing by trunnion-like
pivots 40, 40 laterally aligned with the universal joint 30.
The support cylinder 34 has a flattened upper surface 42 on which a
multi-toothed tilt locking and release rack 44 is integrally formed
or is otherwise secured. This rack is a sector gear member whose
teeth have multiple engagement with meshing teeth 46 in the head 48
of a tilt locking and release dog 50 for minimized lash. This
locking and release dog is pivotally mounted to the tilt cylinder
38 by laterally extending pivot pin 52 and can swing upwardly in a
limited arc as determined by the clearances within the tilt
cylinder. The head of the locking and release dog is formed with a
curved camming slot 54 through which a laterally extending
actuating lever 56 projects. As shown by FIGS. 2 and 4, the inboard
end of the lever is pivoted to the tilt cylinder by an upwardly
extending pivot pin 58 and projects from this pin through the
curved camming slot 54 in the tilt locking and release dog. Lever
56 extends laterally outwardly from the tilt head assembly through
an elongated exit slot 60 laterally formed in the tilt cylinder. An
external knob 62 is provided on the free end of lever 56 for
convenient manual gripping by the vehicle operator when a change in
angular position of the tilt head assembly is desired. Lever 56 has
a generally spherical camming member 64 formed thereon which slides
in the curved camming slot 54 when the lever is swung on its pivot.
A connector 66 is interposed in the lever 56 outboard of the tilt
release dog and within the confines of the tilt cylinder. This
connector has a cylindrical recess 67 for receiving one end of a
helical compression return spring 68 for the lever 56. This spring
extends longitudinally within the tilt cylinder 38 and is seated in
a cylindrical spring pocket 69 formed therein. The spring 68
normally forces the lever forward so that camming member 64 is in
the forward portion or locking part of the camming slot and in an
over-center position with respect to the pivot axis A of the tilt
head assembly to provide a positive lock and the positive holding
of the tilt head assembly in any selected adjusted position.
By swinging the lever rearwardly and manually about the tilt
release lever pivot pin 58, the camming member 64 will move
rearwardly and in the slot to force the tilt release dog 50 to turn
in an upward and clockwise direction to effect disengagement of the
teeth of the dog and the rack 44. When this occurs, the tilt head
assembly can be tilted to various angular positions illustrated in
FIGS. 1 and 3.
To assist in this movement, there is a helical compression spring
71 which provides a spring force to urge the tilt head assembly to
pivot on axis A in a counterclockwise and upward direction. This
spring is seated in a bore in the tilt cylinder 38 and extends
therefrom into engagement with an elongated spring guide 70 which
is seated on a protuberance 72 of the support cylinder. A
cylindrical plastic cover 74 disposed around the tilt cylinder
provides a finely finished appearance for the tilt head
assembly.
Assuming the tilt assembly is in one of its lower tilt positions
and the lever 56 is manually turned rearwardly by the vehicle
operator to effect release of the dog, the spring 71 will force the
tilt head assembly to pivot upwardly until the manual lever is
released to effect automatic multi-toothed engagement of the
locking dog with the rack 44. This automatic engagement occurs
since spring 68 forces the tilt release lever to its forward or
locking position in the camming slot and in an over-center position
with respect to the tilt axis. Under these conditions, any turning
force directed to the steering wheel will not effect disengagement
of the dog and undesired tilting of the tilt head assembly.
To move the tilt head assembly downward from any upper position,
the tilt lever is manually pivoted toward the operator and held
against the action of the lever return spring. The tilt head
assembly is then manually moved or turned on the pivot axis A
downwardly to a selected position at which point the lever is
released so that the spring 68 can again effect the movement of the
lever in the camming slot and the positive locking of the tilt head
assembly.
While a preferred embodiment of this invention has been shown and
described to illustrate the invention, other embodiments will
become apparent to those skilled in the art. Accordingly, the scope
of this invention is set forth in the following claims.
* * * * *